Use of ultrasound in occupational risk assessment of low-back pain.

The aim of the study was to evaluate ultrasound technique in preemployment medical assessment of the risk for low-back pain. Volunteers for the study were recruited among agricultural workers employed in the "Agraria Department" of the University of Bologna, Italy. The group consisted of 90 subjects, 52 male and 38 female, aged 25 to 58 years. The subjects filled in a questionnaire on medical history of low-back pain and were examined using an ultrasonograph equipped with a high linear frequency probe (3.5 MHz). The oblique parasagittal diameter of the lumbar spinal canal was measured by transabdominal ultrasonic imaging in the lumbar (L4-L5) and lumbosacral (L5-S1) region. Individuals with significantly narrower canals (< 14 mm) had an increased risk of low-back pain. The paper concludes that ultrasound imaging could become a valuable screening tool in industry, permitting selective job placement for workers at high risk for disorders of the back.